Remove Qt SVG and Qt OpenGL as hard dependencies
Qt SVG is not used in the frontend (no SVGs are rendered).
Neither is Qt OpenGL used. Qt OpenGL is discouraged anyway.
foreach(dir
Fonts
Forts
Graphics
Locale
Maps
Missions
Music
Names
Scripts
Sounds
Themes
misc
)
add_subdirectory(${dir})
endforeach(dir)
if(${GL2})
add_subdirectory(Shaders)
endif(${GL2})